I have a 64-bit MacBook Pro (Intel Core i5) running OS X version 10.8.4 (Mountain Lion), and want to install Ubuntu 16.04.1 (Xenial Xerus) on an existing empty partition of my external hard drive. This apparently requires creating a bootable DVD, CD, or USB flash drive, so I’m trying to create a bootable DVD-R. Unfortunately, when I download the disk image, open Disk Utility, select File → Open Disk Image..., choose the correct image file, and click Open, I get an error message, "Unable to attach "ubuntu-16.04.1-desktop-amd64.iso." (no mountable file systems)".
There are several existing pages on askubuntu.com that address issues like this, but most of them are at least 4 years old and appear no longer relevant. For example, How do I get my Mac to boot from an Ubuntu USB key? suggests using a Mac-specific ISO (amd64+mac), but I can’t find a mac-specific ISO of Xenial.
Thanks in advance for your help!
I was going to include here the URLs for several pages I've already looked at that didn't solve the problem (mostly on ubuntu.com and askubuntu.com), but unfortunately since this is my first post, my reputation is zero and I'm limited to two URLs. I used one of those URLs above. The other is http://forums.macrumors.com/threads/dd-usb-to-partition.1329407/ ; it has instructions like "+Use UNetbootin to install the files to the root drive (usb)", which are too vague/unfamiliar for me.
Another web page suggested
hdiutil attach -verbose -noverify -nomount downloaded_ubuntu.iso. I did in fact open Terminal and enter that string, but I got errors like
CBSDBackingStore::newProbe stat() failed. No such file or directory.
Update after one comment from muru and two comments from CelticWarrior:
Thanks very much for pointing out some silly mistakes I made. (There were reasons! I swear there were reasons!) Unfortunately, correcting the mistakes didn’t solve the problem.
muru: I tried replacing “downloaded_ubuntu.iso” with the full path and file name when following the advice at Why can't I mount the Ubuntu 12.04 installer ISOs in Mac OS X?
CelticWarrior: I tried burning the DVD from the Finder instead of from Disk Utility. Also, I found https://help.ubuntu.com/community/BurningIsoHowto , which had slightly different Disk Utility instructions than what I’d been doing, and tried those as well.
But I keep getting results like:
o The DVD burns and verifies successfully, but the ISO file doesn’t get unpacked, only copied. So the DVD contains one file in ISO format.
o The DVD seems to burn and verify successfully, but then I get the error, "The disk you inserted was not readable by this computer."
o Before I get to the stage of burning the DVD, I get the error, "Unable to attach "ubuntu-16.04.1-desktop-amd64.iso." (no mountable file systems)"
It’s not trivial if I can't get it to work! :-P
Thank you for helping me with this.